The present invention relates to a new and distinct cultivar of Nepeta named ‘Cat's Pajamas’. The new plant resulted from a cross between Nepeta faassenii ‘Purrsian Blue’ U.S. Plant Pat. No. 24,788 as the female or seed parent and a proprietary unnamed selection of Nepeta phylloclamys (non-patented) as the male or pollen parent on Jun. 6, 2013. Seed was harvested in the summer of 2013 and given the breeder code 13-13-5 during the final trial stages of the summer of 2015. The new plant was selected based on the early blooming and compact habit traits. The new plant has been asexually propagated by division in 2015 and shoot tip cuttings since the spring of 2016 with the resultant plants remaining identical to the original plant, stable and true to type in successive generations.